JPS61148338A - Inspector - Google Patents

Abstract

PURPOSE:To automatically observe the presence of bubbles generated from an object to be inspected, by placing a box body having a transparent bottom above the object being inspected immersed in a fluid to provide an optical detection mechanism therein to recognize bubbles from the object being inspected. CONSTITUTION:First, an inspection liquid 3 in an inspection tank 1 is heated with a heater 2 up to a specified temperature and then, a semiconductor device 5 placed on a base 4 is immersed into the inspection liquid 3 to a specified depth together with the base. Then, a camera cell 6 is lowered above the semi conductor device 5 to make a camera 8 focus on the undersurface of the trans parent bottom of the camera cell 6. Then, a TV camera 8 detects an image of a gas sealed into a semiconductor element (not illustrated) which leaks out side the semiconductor device 5, rising as bubbles 7 in the inspection liquid 3 as the semiconductor device is heated by the inspection liquid 3. Then, the results are provided to a display unit 12 as image signal via a binary coding section 10 and a judging section 11 to show the presence of bubbles 7.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an inspection technique, and in particular, to an effective technique commonly used for inspecting the airtightness of a sealing structure that encapsulates a semiconductor element in the manufacture of semiconductor devices.

[Background Art] In the manufacture of semiconductor devices, a sealing body (made of ceramic or the like) is used to protect a semiconductor element made of, for example, silicon from external moisture or impurities.
The semiconductor device is shipped by encapsulating it in a puff cage (puff cage).

In this case, if the airtightness of the puff cage is incomplete, external moisture or the like will enter the semiconductor device after shipping, causing corrosion or the like to the semiconductor element, which will cause a decrease in the reliability of the semiconductor device.

For this reason, the airtightness of the package in which the semiconductor element is encapsulated is usually inspected prior to shipment.

The following can be considered as an airtightness test for such a semiconductor device.

That is, the semiconductor device is immersed in a fluid such as ethylene glycol that is heated to a predetermined temperature.

At this time, if the airtightness of the package containing the semiconductor device is incomplete, the gas sealed in the puff cage together with the semiconductor device will heat and expand, and the semiconductor device will be immersed through the sealing part of the package or other defective parts. leaks into the fluid and is observed as bubbles.

Then, an operator visually observes the presence or absence of bubbles in this fluid to determine whether or not the semiconductor device is airtight.

However, the method of visually observing the bubbles generated as described above requires continuous concentration on the part of the operator for a long period of time, resulting in low efficiency and reliability of the inspection process. The inventor has discovered that this is a cause of decreased productivity in the inspection process, such as by hindering automation.

In addition, as a document explaining the airtightness inspection of semiconductor devices, there is "Integrated Circuit Handbook jP292" published by Maruzen Co., Ltd., November 25, 1961.

[Object of the Invention] An object of the present invention is to provide an inspection technique with good productivity.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Summary of the Invention] A brief overview of typical inventions disclosed in this application is as follows.

That is, the transparent bottom part is placed above the object to be inspected, which is immersed in a fluid maintained at a predetermined temperature, and is immersed below the surface of the fluid. A test object immersed in a fluid is equipped with a box that captures air bubbles and an optical detection mechanism located inside the box that detects air bubbles captured in the transparent bottom of the box. This makes it possible to automatically observe the presence or absence of air bubbles generated from the air bubbles without the operator's visual inspection, thereby improving productivity in the inspection process.

[Embodiment 1] FIG. 1 is a schematic cross-sectional view of an airtightness testing device that is an embodiment of the present invention.

A heater 2 is provided at the bottom of the transparent test tank 1, and is configured to heat a test liquid 3 made of, for example, ethylene glycol, stored inside the test tank 1 to a predetermined temperature.

Also, in the test liquid 3 heated to a predetermined temperature, a semiconductor device 5 (for example, a semiconductor device 5 (which has a semiconductor element sealed in a hermetically sealed package) placed on a movable mounting table 4) is placed on a movable mounting table 4.
(object to be inspected) is immersed.

Above the semiconductor device 5 immersed in the test liquid 3, a transparent camera tank 6 (box) with a horizontal bottom is provided so as to be able to move up and down. It is configured such that air bubbles 7 generated from the semiconductor device 5 immersed in the test liquid 3 below and rising in the test liquid 3 are attached and captured.

Reference numeral 7 is a device which is extinguished by lifting the camera tank 6 at a predetermined time and exposing the bottom to the air, so that the semiconductor devices 5 can be inspected repeatedly.

Furthermore, an independent moving mechanism is provided inside the camera tank 6 so that the television camera 8 can be raised and lowered simultaneously with the camera tank 6 so that the optical axis is in the vertical direction, or can be raised and lowered separately. The camera is focused on a portion of the lower surface of the transparent bottom of the camera tank 6 where the bubble 7 is captured.

The camera tank 6 is configured to detect air bubbles 7 captured on the transparent bottom surface of the camera tank 6, which is illuminated at a predetermined illuminance by an illumination mechanism 9 provided at a predetermined position outside the inspection tank 1.

In this case, the image signal detected by the television camera 8 is converted into a digital signal based on a predetermined threshold value in the binarization unit 10, and further in the determination unit 11, for example, the brightness and darkness of the observation field set in advance are determined. By comparing with the ratio etc., you can find out whether or not there is a habit 7! ! The presence or absence of bubbles 7 is displayed on a display unit 12 such as a cathode ray tube.

The operation of this embodiment will be explained below.

First, the test liquid 3 stored in the test tank 1 is heated to a predetermined temperature by the heater 2 provided at the bottom of the test tank 1.

Next, the semiconductor device 5 placed on the mounting table 4 is immersed together with the mounting table 4 to a predetermined depth below the surface of the test liquid 3.

Thereafter, the camera tank 6 is lowered above the semiconductor device 5 immersed in the test liquid 3, and the transparent bottom part is stopped at a predetermined position below the surface of the test liquid 3.

At this time, the TV camera 8 in the camera tank 6 is also moved downward as the camera tank 6 descends, and the focus of the TV camera 8 is set on the lower surface of the transparent bottom of the camera tank 6.

If the sealing package made of ceramic or the like for the semiconductor device 5 immersed in the test liquid 3 is not airtight, the semiconductor element (
(not shown) and the gas sealed in the semiconductor device 1f.
5 is heated by the test liquid 3 around the semiconductor device 5, expands, leaks to the outside of the semiconductor device 5, becomes bubbles 7, rises in the test liquid 3, and is captured and stopped by the transparent bottom of the camera tank 6. Ru.

The image of the air bubbles 7 captured on the transparent bottom of the camera tank 6 is detected by the television camera 8 in the camera tank 6, and the air bubbles are displayed as an image signal on the display unit 12 through the binarization unit 10 and determination unit 11. The presence of 7 is displayed.

In this case, the image of the bubble 7 at the bottom of the camera tank 6 is detected, for example, as a change in brightness within the observation field of the television camera 8, and the presence or absence of the bubble 7 is determined by comparing it with the ratio of brightness and darkness within the field of view set in advance. can be quickly determined.

In this way, since the presence or absence of bubbles 7 from the semiconductor device 5 immersed in the test liquid 3 is automatically checked without the operator's visual inspection, the test is accurate and quick, and the production of the test process is improved. performance is improved.

After a predetermined period of time has elapsed, the camera tank 6 is raised together with the television camera 8, and the bottom of the camera tank 6 is exposed to the air.
The trapped air bubbles 7 are extinguished.

In this case, for example, a wiper mechanism (not shown) that slides in close contact with the lower surface of the bottom of the camera tank 6 is provided, and the camera tank 6 is
It is also possible to adopt a structure in which the trapped air bubbles 7 are removed after determining the presence or absence of the air bubbles 7 at the bottom.

Thereafter, the semiconductor device 5 placed on the mounting table 4 is raised together with the mounting table 4 and taken out of the inspection tank 1 .

By repeating the above series of operations, the airtightness test of a large number of semiconductor devices 5 is quickly performed.

Furthermore, since a series of inspection operations are automatically performed as described above, it is possible to combine them with automated processes such as the sealing process before and after the inspection process and the shipping and packaging process, thereby completing the entire manufacturing process of the semiconductor device 5. productivity will be improved.

[Embodiment 2] Fig. 2 shows one piece of airtightness inspection sticker according to another embodiment of the present invention. This embodiment differs from the first embodiment in that it is tilted by an angle and the television camera 8 is installed perpendicular to the tilted bottom, but the rest is the same.

That is, by tilting the bottom surface of the camera tank 6 as described above,
By configuring the television camera 8 to be perpendicular to the inclined surface, bubbles 7 generated from the semiconductor device 5 immersed in the test liquid 3 are moved along the inclined surface of the transparent bottom of the camera tank 6. TV camera 8 at a predetermined position on the slope between
Further, the bubbles 7 are sequentially discharged toward the surface of the test liquid 3 without being stagnant on the inclined surface.

As a result, the operations and mechanisms in the first embodiment for eliminating the bubbles 7 at the bottom of the camera tank 6 each time a plurality of semiconductor devices 5 are inspected can be omitted, and the airtightness inspection can be carried out efficiently.

[Effects] (1) A box that is movable up and down above an object to be inspected that is immersed in a fluid, and that traps air bubbles generated from the object with a transparent bottom that is immersed below the surface of the fluid. The device is equipped with an optical detection mechanism located within the box body that recognizes air bubbles trapped in the transparent bottom of the box body, thereby detecting air bubbles generated from the test object immersed in the fluid. The presence or absence can be automatically observed without visual inspection by the operator, improving productivity in the inspection process.

(2) Because the transparent bottom of the box is tilted at a predetermined angle from the horizontal plane, air bubbles generated from the object to be inspected are sequentially removed from the bottom of the box without stagnation, eliminating air bubbles. It is possible to omit the operations and mechanisms required for inspection, and inspections can be carried out efficiently.

(3) As a result of the above (1), the airtightness of the inspected object can be determined accurately, and reliability in the inspection process is improved.

Although the invention made by the present inventor has been specifically explained above based on Examples, it goes without saying that the present invention is not limited to the Examples and can be modified in various ways without departing from the gist thereof. Nor.

For example, one side of a transparent test tank is tilted toward the inside of the test tank, air bubbles generated from semiconductor devices are configured to rise along the slope, and a TV camera for observing the bubbles is placed outside the test tank. It is also possible to have a structure in which the

[Field of Application] In the above explanation, the invention made by the present inventor has been mainly applied to the field of application which is the background of the invention, which is the hermetic inspection technology of semiconductor devices. It is also possible to apply this method to inspection techniques for airtight structures such as wristwatches.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of an airtightness testing device that is an embodiment of the present invention, and FIG. 2 is a schematic sectional view of an airtightness testing device that is another embodiment of the present invention. l... Inspection tank, 2... Heater, 3... Test liquid (fluid), 4... Mounting table, 5... Semiconductor device (tested object), 6... Camera tank (box body), 7... air bubbles, 8...
・TV camera (optical detection mechanism), 9... lighting mechanism,
10... Binarization section, 11... Judgment section, 12... Display section. Figure 1 Figure 2

Claims (1)

[Claims] 1. An inspection device that tests the airtightness of an object to be inspected by detecting bubbles generated from the object immersed in a fluid at a predetermined temperature, A box body that is movable up and down above an object to be inspected and that captures air bubbles generated from the object to be inspected with a transparent bottom that is immersed below the surface of the fluid; An inspection device comprising an optical detection mechanism that detects air bubbles trapped in the transparent bottom of the device. 2. The inspection device according to claim 1, wherein the transparent bottom of the box is inclined at a predetermined angle from a horizontal plane. 3. The inspection device according to claim 1, wherein the optical detection mechanism is a television camera. 4. The inspection apparatus according to claim 1, wherein the object to be inspected is a hermetically sealed semiconductor device.